Polar ice caps

Glacial retreat: The shrinking or melting of glaciers over time due to warmer temperatures.

Sea level rise: An increase in the average level of the world's oceans caused by melting glaciers and thermal expansion.

Albedo: The measure of how much light is reflected back off a surface. High albedo surfaces reflect more light (such as snow-covered polar ice) while low albedo surfaces absorb more light (such as dark asphalt).